Thermodynamic theory of two-dimensional to three-dimensional growth transition in quantum dots self-assembly

A thermodynamic model has been proposed to address the transition from the two-dimensional to three-dimensional growth modes in the quantum dots self-assembly. It was found that the surface energy density of substrates and the mismatch between quantum dots and substrates play key roles in the transition of the growth modes. The high (low) surface energy density of substrate and the low (high) mismatch between quantum dots and substrate result in the large (small) critical thickness of the wetting layer, which further determines the growth mode of quantum dots. These findings suggested that we could control the transition of the quantum dots growth mode by substrate manipulation. The theoretical results were consistent with experimental observations, which implied that the established thermodynamic theory could be expected to be a general approach for pursuing the evolution of the growth mode in the quantum dots self-assembly.